Electric switch for electric lamps and the like.



' A. H. MILLER.

ELECTRIC SWITCH FOR ELECTRIC LAMPS AND THE LIKE.

APPLICATION FILED MAY I0, 1906- Patented Aug. 10, 1915.

ANDREW H. MILLER, OF DETROIT, MICHIGAN.

ELECTRIC SWITCH FOR ELECTRIC LAMPS AND THE LIKE.

Specification of Letters Patent. Patefited Ailg, 10, 1915.

Applicationfiled May 10, 1.906. Serial No. 316,180.

with other electrically operated advertising,

devices. r

The invention seeks to provide a simple and effective form of flashing switch by which the intensity of the lamps can be automatically dimmed and intensified or other electrical devices automatically operated.

Further objects of the invention are to provide a thermostatic flashing switch in which a single switch member of homo geneous metal or alloy can be employed in place of the usual two-metal thermostat, and to provide an automatic flashing switch which may be economically manufactured, which can be readily adjusted and which will not readily get out of order orout of adjustment or be afiected by vibration.

With these objects in view the invention consists in the features of construction, combinations and arrangements of "parts hereinafter set forth, illustrated in the ac companying drawings and more particularly pointed out inthe appended claims.

' In the drawings, Figure 1 is a diagram illustrating the manner of connecting the improved switch to a number of lamps forming a sign. Fig. '2 is a plan of the improved switch. Fig. 3 is a view partially in elevation and with parts shown in section on the line 33 of Fig. 2. Fig. t is a cross section on the line H of Fig. 3. I

Advertising signs and the like contain ing a number of electric lamps have usually been flashed up and down by expensive motor driven switch mechanism. The present invention provides a simple thermostatic device, the thermostatic switch to form the letters of a sign, or in any other member of which is preferably in the form suitable manner, are connected; in parallel with the line wires 11 and 12. Line wire 11 is connected to one pole of the battery 13 or other source of current, the other pole of which is connected to one terminal of the switch by wire 14. Line wire 12 is connect 'ed to the other switch terminal.

The flashing switch is mounted upon a baseboard 15 of stone, glass or other suitable material, and comprises a thermostatic switch member in-the form of a bent strip or bow 16, rigidly secured at its ends to the base 15 by bolts or binding screws 17. The ends of the strip are arranged between wash-- ers 18 on the bolt and nuts 19 thereon firmly connect the parts together.

The bent strip or bow 16 is formed of any desirable homogeneous metal or alloy that is highly expans'ible by heat. Its ends are firmly anchored in position, as described, so that the expansion thereof will cause an outward movement of its central portion which is provided with a button or contact 20. The thermostatic switch member or strip 16 is covered, except at its ends and except the centrally projecting button or contact 20, with suitable insulating material 21 such as mica, vulcanized fiber or the like, and upon this insulating cover. is wound a heating coil 22. The heating'coil' for the thermostatic switch member is of ,very small size and of high resistance and comprises a large number of turns. Thisheating coil is preferably formed of German silver or other suitable high resistance mate ,rial. A metal conducting strip 23 of brass or like material, is centrally secured to the base 15 by a bolt or binding screw 24, which extends through the base at one side of and adjacent the central portion of the bent strip or how 16. The conducting strip 23 is bent upwardly and extends over the central portion of the thermostat c switch member or how 16, and a contact screw 25 is adjustably threaded through the metal strip 23 above the button or contact 20'on the thermostatic switch member. A. look nut 26 holds the screw contact 25 in adjusted position.

contact could be arranged upon the opposite no In the form shown, contact 25 is normally 10 side of the switch member so that the movement thereof, when heated, would disengage the contacts Battery wire 1.4: is preferably connected to the binding screw 24 and conducting binding screw 24, The line wire His connected to the binding screw 17 atoneend of the thermostatic switch member 16 by washer 29 and nut 80. "One end of the heat; ing coil 22 is connected to the binding screw 17 at the opposite end of the thermostatic switch member or bow 16 and the otherend of the coil is connected by a wire 31 to the binding screw 24, such wire being'held in "place on the screw by washer 32 and nut 33.

With the connections as described, current will normally flow fromthe battery 13 or other source of power, through wires 1%,

binding post 2-1 and. wire '31, through the heating coil 22 to one end of the bent ther mostatic strip 16, thence through the strip-- 16v on theline wire-1'2, through the lamps bf the sign and back by linewire' 11 to the battery. The heating coil is thus in series with the lamps and its relative resistance is so.

high that'the amount of -current passing through the circuit will be insufficient to light the lamps. The current flowing through the circuit however, will be sufficient to heat the coil22: and thermostatic switch member 16, softhat the latter will ex pand and its central portion moved '0utv wa'rdly until'the contact 20 is brought-into engagement with'the 'contact 25. Upon such en'gagemenna low resistance shunt-is formed around. the heatingcoil and-the current will fiow from battery. 13, or other source-0f power, by line wire 1a,;binding post 24, conducting; strip 23 -to-the engaged contacts 25 and-20,, thence by the strip/'16, binding'post 17 line. wires 12 te -the: lamps: of the. sign' and back as before by line-wirefll to thebatte'ry.

The low resistance circuit-thus formed permits. a lighting current to pass. and the lamps of the sign will. flash out brightly-j But,v inasmuch as, the resistance of thefc'oilf 22- is very high compared toutha t of the 0in cuit formed when the, contactsare: in engagement, only a small; amount, c r te-7' I A, 'cally noeurrent, will flow through theflheat ing coil and the latterand the bow or thermostatic strip 16 Will 0001, andj-when the latter' is contracted sutficifently, the engagedescribed;

merit betweerr contacts 25 and 20 will be broken so that the heating coil is again interposedin the circuit to cut down the current flowing and the lamps will be dimmed -or become entirely dark.

strip 23 by a washer 27 and nut 28 on the Itis obvious that numerous changes may be made in thedetails of structure without departure from the essentials of the invention set forth.

said support to said base, said bowed metal strip having a contact on its outer face, a normally fixed, adjustable contact on said support arranged to cooperate with the contact on-said bowed metal strip, circuit conductors connected tosaid support and to one of the terminals of said strip, and a heating coil wound about said bowed metal strip and connected at its ends to the other terminal thereof andto said conducting support, substantially as described.

. 2. The combination with one or more electric lamps, of'an' automatic flashing switch interposed in the circuit-of said lamps and comprising an insulating base, a thermostatic switch member in the form of a homogeneous, bowed metal'strip, terminal binding posts rigidly securing the ends of said strip to said base, a conducting support on said base, a normally fixed contact adjustably mounted on said support, said thermostatic switchv member having a contact on its outer" face arranged to cooperate with said normal-l'y fixed, adjustable contact, and a heating; coil of relatively high resistance coiled aboutsaidswitch member, said switch member, in closedposition, being arranged, to form a shuntvof relatively low resistance around, said heating coil, substantially as 3 NDREW H; MILLER.

Witnesses: a I

EDWARD-BURNS OAULKINS, WILLIAM E. PHELPS. A 

